The normal menstrual cycle - a regular two-phase cyclic changes in a woman's body that occur under the action of hormones in the genitals and throughout the body. The leading role in shaping and maintaining the menstrual cycle is the central nervous system.

Neurohumoral regulation of the menstrual cycle

The cortex regulates all processes in our body. Under her influence at the end of the prenatal period occurs sexual differentiation of the hypothalamus - a brain region responsible for the endocrine system. Sexual differentiation of the female type is characterized by the fact that in the hypothalamus occurs first tonic or basal (background) secretion of hypothalamic neurohormones that stimulate the release of pituitary gonadotropins - the main endocrine gland located in the brain. Gradually, by adolescence, begin cyclic fluctuations in their secretions. When the differentiation of male pattern occurs only tonic secretion of gonadotropins without undulation their level.

The frequency of the processes during the menstrual cycle is provided by mechanisms of self-regulation: under the influence of hormones of the hypothalamus increases or decreases the secretion of pituitary hormones. Under the influence of hormones of the pituitary gland is stimulated or inhibited the secretion of sex hormones produced by the ovaries of women. Under the influence of sex hormones occur cyclical changes in the genitals and around the woman's body.

Hormones, which flows under the influence of the menstrual cycle

The hypothalamus secretes hormones that provide interaction between the central nervous system with the endocrine system. These hormones are called Riesling, Riesling, hormones or factors. Hypothalamic hormones that stimulate the secretory activity of the pituitary gland, called liberinami and overwhelming - statins. Each hormone stimulates the hypothalamus and inhibits the secretion of only one pituitary hormone. Riesling-factor, stimulates the secretion of pituitary follicle-stimulating hormone called folliberinom and luteinizing - lyuliberinom.

Under the influence of hormones produced by the pituitary follicle-stimulating hormone (FSH - its longer in the first phase of the menstrual cycle), and luteinizing hormone (LH - hormone second phase of the menstrual cycle). HCG ensure the development and maturation of the follicle, ovulation, development and operation of the corpus luteum, the synthesis and secretion of sex hormones - estrogen, progesterone and androgen.

In ovarian follicles under the influence of FSH in the first half of the menstrual cycle, estrogens are formed under the influence of which is the development of blood vessels in the uterus growth of uterine mucosa, rhythmic contractions.

In the second half of the menstrual cycle in the corpus luteum, formed on the place of the bursting of the follicle, it is produced mainly another female sex hormone - progesterone (but estrogen also produces the corpus luteum). Under the influence of progesterone begin to function gland mucosa of the uterus and decreased muscle tone of the uterus - that is, there are processes that prepare the uterus for implantation of the fertilized egg and the formation of the placenta.

Cyclical changes during the menstrual cycle

The menstrual cycle occurs in two phases, which shares the ovulation - release egg from the ovary. During the first phase under the influence of FSH and estrogen there is a maturing egg in the ovary - a girl born with already laid down in the ovaries of eggs, each of which matures during a single menstrual cycle (egg nature has a margin of at childbearing age they are not only missing, but remain). The egg matures in a special bubble - the follicle, which is also a temporary endocrine gland as highlights estrogens.

When the central nervous system receives signals that the egg has matured dramatically hormonal changes: reducing the amount of FSH and LH increasing the number. Under the influence of hormones follicle bursts and the egg is released from the ovary. This point is called ovulation. At the site of the ruptured follicle forms a new temporary endocrine gland - the corpus luteum, which begins to produce progesterone and estrogen. The second phase of the menstrual cycle The phases of the menstrual cycle failures unacceptable   It occurs under the influence of LH and progesterone.

Oocyte first goes into the abdominal cavity, and then enters the fallopian tube and moves it toward the uterus. Here, the egg can meet the sperm that will fertilize the egg and it will turn into an embryo. Within a week after fertilization, the embryo moves along the oviduct, and then enters the uterine cavity and is embedded in the mucosa.

If pregnancy does not occur, the effect of LH abruptly interrupted stops producing progesterone, which is restrained and uterine lining of the uterus is torn away, followed by bleeding - menstruation.

According to the menstrual cycle The menstrual cycle - that occurs in different phases?   a woman can be judged on its ability to conception Conception - as the emerging life , Pregnancy and childbirth.

Galina Romanenko

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